The Pebble wristwatch has an e-paper screen able to show different watchfaces. Photograph: Kickstarter.com

In the old Dick Tracy comics, the detective had a wrist TV-cum-mobile he used to talk to his associates. Now something that looks just like it is days away from production after a Silicon Valley startup raised more than $8m (£5m) from individual pledges to build a watch that will connect to the internet and run apps.

Eric Migicovsky, 25, the founder and lead designer of Pebble, has found serious enthusiasm for the idea. He began with a modest ambition a month ago: raise $100,000 from a few hundred people willing to order a watch and pay upfront.

The $115 watch has an e-paper face (like a small version of the Kindle) able to show different watchfaces, run sports and fitness apps and show notifications from your phone (such as new emails).

He put up a page on Kickstarter.com – a "crowdfunding" site popular with filmmakers, musicians and tech companies – and sat back. Within two hours, the initial target was hit. By Friday more than 56,000 backers had pledged between $99 and $10,000.

"We had a factory in San Jose ready to make about 1,000 Pebbles if we were able to raise the initial funding," Migicovsky told the Guardian. "Right now we've got 56,000 who have pledged money. People have ordered anywhere between two and 100 each. In all, we're going to make more than 67,000."

It has been an astonishing ride. The idea is that the Pebble watch will be able to run specific apps: among the plans are one for runners, another for cyclists, another that would show your email inbox or control your iPhone, all while being waterproof.

The Pebble team have been designing smart watches for three years, and had already built one to work with BlackBerry phones (which sold about 1,500 watches and attracted 80 apps). The surge of interest came when the company decided to build one for Apple's iPhone and phones running Google's Androidsoftware.

"It's probably the iPhone part that's driven it," Migicovsky said. "Also, people are excited about apps. It's not just a watch that you buy – your watch will actually get better as you develop apps. We're excited about what people will make with it."

The idea of a watch that connects to the internet is not new; Microsoft's Bill Gates showed off a watch called Spot (for smart personal object technology) in 2004. But it was, like many of Gates's best ideas including the tablet computer, too far ahead of its time: in 2008 Microsoft stopped offering the $800 devices, and in January this year it turned off the data service that ran them.

"It was a nice product, but too early," Migicovsky said. "The early ones had to connect to the internet themselves, because there weren't smartphones around like today."

The huge funding does not mean the team is rolling in money. "We're spending every spare dollar we have," Migicovsky said, explaining that after Kickstarter and Amazon take their respective 5% and 3% fees (for hosting the fundraising and processing the cheques), the margins will still be narrow.

He tried – and failed – to win backing from Silicon Valley's more traditional investors, venture capitalists: "What they told me was that hardware is a risky business and they didn't want to take that risk."

There is, though, one loser from the frenzy: the factory in San Jose. Migicovsky is now looking to China to fulfil the gigantic demand because the economies of scale, and manufacturing, favour going there.